I’m having a few issues with getting volumetric lighting to work properly. When I render I get a very grainy image. I’ve looked everywhere for a
I have tried setting Clamp Indirect to just about every number to 100 and it doesn’t seem to do anything.
Rendering at 2000 samples also gives lousy results.
I tried following what Gleb Alexandrov posted here:
homeless_christmas.blend (10.7 MB)
Even without the volume effects this is not a scene Cycles is very competent with: A large space with multiple small light sources is kind of a nightmare scenario for an unoptimized path tracer.
That’s a totally different situation than Gleb Alexandrov’s scene with its single, rather large area light. Didn’t have time to look at your file, but I tend to say that regardless of any potential for optimization, this will be very costly to render in any case (= samples galore).
That is discouraging. Thanks for reply.
This is a quick test render with your scene (1000 samples) - had to replace the textures, as they were not included in your download. Mostly OK, but of course you see the issues with the tiny light sources…
How do you add the fog? By using the setting in the World tab?
That already looks way better than what I’ve been able to achieve!
To create the volumetrics I creaded a cube that went around the whole scene and changed it’s material to I believe volume scatter.
That’s why I did, too…
Didn’t change your render settings at all, but recreated most materials from scratch: I just don’t trust this PBR-node stuff…
The “fog” material is just Volume Scatter with a density of 0.05 and 0.95 anisotropy.
You are awesome. I will try with non PBR materials when I get some time today. Thank you for taking the time to look into this for me!
I’m not entirely sure if they were alone to blame (if at all)…
On further inspection I might also have increased the volume bounces to 4 (Render > Light Paths), not sure actually.
I swapped out the PBR materials for just a regular diffuse and still the same results. I used the settings you had used and even at 2000 samples still very hard to make out the image through all the grain.
Does computer power impact the final image? I’m using a lower end laptop right now.
I have uploaded the .blend with the textures and I apologize as the previous blend file was incomplete.
Your “world”, the object Sphere.001, is spoiling things. Delete it and the render should immediately look much nicer…
Sorry, I totally forgot that I deleted/disabled that as well because it missing the texture anyway.
Reason for the render trouble (I guess): Sphere.001 is turning the scene into an enclosed space, which forces Cycles to calculate a whole lot of “nothingness” and light bouncing around where the camera can’t see it anyway. And even more tiny emissive spots don’t help either, I guess…
That did it! I completely forgot that I made that and hid it from view. I was trying everything I could to light my scene, haha.
Thank you so much, now I can finally play with some settings and actually see what’s going on in my scene!
